DOC: Fast and accurate congestion analysis for global routing

This work presents a fast and accurate congestion analysis tool at the global routing stage. It focuses on capturing the difficult-to-solve congestion in global routing designs. The proposed framework identifies the routing congestion using a novel Orthogonal Congestion Correlation (OCC) factor, which identifies the hard-to-route hot-spots. A key contribution of this work is a fast global router to minimize congestion caused by long nets and accurately reveal the distribution of hard-to-route spots due to high density short nets. The global router uses a dynamic representation of net to allow fast topology transformation. The proposed framework can evaluate the routability of a placement solution, and be utilized to aid the placer for a congestion-aware design.